Letter to Science re Osborn and Briffa Data

The continued negligence of the major journals in ensuring that paleoclimate authors archive data in accordance with journal policies is very frustrating and, as previously noted, has reared its ugly head once again with Osborn and Briffa. I have had little luck in the past with Science (except for the Kilimanjaro sample dO18 data) but here’s one more go. I think that Benny Peiser is planning to encourage CCNet readers to write Science ( bhanson at aaas.org) in support of this request.

Science supports the efforts of databases that aggregate published data for the use of the scientific community. Therefore, before publication, large data sets … must be deposited in an approved database and an accession number provided for inclusion in the published paper.

In addition, I am also writing to remind you of the similar continuing failures in connection with Esper et al [2002] and Thompson’s Dunde and Guliya ice cores, both of which are cited directly or indirectly in Osborn and Briffa, and about which we have corresponded in the past without any positive outcome.

We note that D’Arrigo et al. [2006] have arrived at precisely opposite conclusions to Osborn and Briffa [2006] on the relationship several Osborn and Briffa sites (Jaemtland, Boreal, Upperwright) to gridcell temperatures. In some cases, although Osborn and Briffa appear to say that they have used identical sites to Esper et al. [2002], the attributions of some datasets seem to differ (e.g. Esper et al. attribute a Quebec dataset to Payette and Filion, whereas Osborn and Briffa cite cana169.) Obviously, the exact data, as contemplated under Science data archiving policies, is necessary to reconcile these differences.

Accordingly, would you please ensure that authors Osborn and Briffa provide a complete archive including the following information:

1. Digital versions of all 14 series as used in their final compilations;

2. For each of the tree ring sites analysed (both the 11 retained and Esper site not used, including Gotland, Jaemtland, Mackenzie Mts and Zhaschiviersk), an exact data citation to a public archive (e.g. WDCP) for the data set used; or, in the alternative, an archive of the data set at the Science website. In cases, where the publicly archive dataset for a site is related to but different from the version used by Osborn and Briffa, please archive the data set as used.

3. Digital versions of the specific gridcell temperature series used in each of the reported temperature correlations together with version date.

Would you similarly ensure that Esper et al. also provide a complete archive including the following information:

4. Exact data citations to a public archive for all datasets used, or, if such do not exist, an archive of the data set at the Science website.

5. A clear and operational definition distinguishing “linear” and “nonlinear” trees, preferably with source code showing any differences in methodology.

Osborn and Briffa [2006] use a composite from Yang et al [2002], which uses data from Thompson’s Dunde and Guliya ice cores, previously published in Science. As discussed in previous correspondence, there are several inconsistent grey versions of this data, which cannot be reconciled on the present record. We have previously corresponded about this without any information being provided by Thompson. The matter has re-surfaced once again with Thompson’s grey data once again being used indirectly in Osborn and Briffa [2006]. This is a very unsatisfactory situation. Would you please ensure that:

6. Thompson provides a complete archive of both Dunde and Guliya ice cores, including both isotope and chemical data.

I wonder if some of the archiving problems stem from the use of graduate students to do pieces of the work, and they can’t remember just what they did or where they put the files they used. These guys may not even be able to replicate their own work!